"Was it 'un-Christian' of weapons manufacturers in the Allied countries to arm the forces that ended the Axis campaign of genocide?," asks Kurt Hofmann in the article linked above from the Jews for the Preservation of Firearms Ownership web site on 24 June 2015.
That deeply clericalist mentality is disturbing, that would use the papacy to sway prudential judgments that belong uniquely to the laity. While the pope is doing some remedial study in the Catechism of the Catholic Church (around paragraph 2263 et seq.) he might also look up subsidiarity (paragraph 1883 - 1885), as well as the role of the laity (around paragraph 2442):
It is not the role of the Pastors of the Church to intervene directly in the political structuring and organization of social life. This task is part of the vocation of the lay faithful, acting on their own initiative with their fellow citizens.